Economic evaluation of crossbreeding for dairy production in a pasture based production system in Kenya

Publication Type

Journal contribution (peer reviewed)

Authors

Kahi,A.K.; Thorpe,W.; Nitter,G.; van Arendonk,J.A.M.; Gall,C.F.

Year of publication

2000

Published in

Livestock Production Science

Band/Volume

65/

Page (from - to)

167-184

Data on life performance of crosses of Ayrshire (A), Brown Swiss (B), Friesian (F) and Sahiwal (S) cattle collected over a 21-year period from a dairy ranch in the lowland tropics of Kenya were analysed to estimate additive and non-additive genetic effects on economic traits. These were used to predict and compare performance of cows and of production systems under nine crossbreeding strategies; namely:: first cross (F x S), two-breed rotation (AS)rot three-breed rotation (BFS)rot and two- (F and S), three- (B, F and S) and four- (A, B, F and S) breed synthetic (Syn) breeds based on equal and unequal contributions of the foundation breeds. B and F additive breed effect for profit per day of productive herd life (PLD), was not significantly different from that of A; it was negative and significant (P < 0.01) for S indicating lower PLD than that of B. taurus. Dominance effects for PLD in A x S and B x S were positive and significant (P < 0.05). Additive x additive interactions were negative and significant in all the crosses. Ranking of strategies for PLD was: F x S, (3/4F 1/4S)(Syn), (FS)(Syn), (BFS)rot and (ABFS) (Syn). Production systems based on F x S were superior to those based on rotations at all levels of number of calvings (NL) and superior to those based on the two-breed synthetics only at NL higher than 4. Variation of costs and prices greatly affected predicted economic benefit but not ranking of strategies. The absence of significant differences in additive breed effects of the B. taurus breeds for PLD showed that comparable economic benefits were derived by use of any of the three breeds for continuous crossbreeding with the S in a production system achieving 3000 kg lactation yields. Economic benefits from the development of two?breed synthetic breeds based an A, B or F are also expected to be comparable in production systems achieving lower yields